scholarly journals Improvement of Fatigue Limit and Rendering Crack Harmless by Over-Moment Loading for Spring Steel Containing a Crack in the Stress Concentration Zone

2012 ◽  
Vol 78 (793) ◽  
pp. 1266-1274
Author(s):  
Keiji HOUJOU ◽  
Koji TAKAHASHI ◽  
Kotoji ANDO ◽  
Katsuya OTSUKA
Keyword(s):  
Stress Concentration ◽  
Fatigue Limit ◽  
Spring Steel ◽  
Stress Concentration Zone ◽  
Concentration Zone

Roadway Deformation Test for Machine Excavation Disturbance

2012 ◽  
Vol 616-618 ◽  
pp. 370-375
Author(s):  
Shan Yang Wei ◽  
Lei Wang ◽  
Teng Li ◽  
Tian Bao Gao ◽  
Ming Liu
Keyword(s):  
Stress Concentration ◽  
Stress Concentration Zone ◽  
Concentration Zone ◽  
Stable Convergence ◽  
Working Face ◽  
Deformation Amount ◽  
Wall Deformation ◽  
Deformation Test ◽  
Roadway Deformation

It can be concluded that two abreast near ways were suffered disturbed effects by one another in the cause of one’s excavation by studying the disturbed effects between JI17-22300 air way and machine way of JI16-22320 working face in the course of excavation ofJI17-22300 air way in Pingmei Shares Shikuang. We found three kinds of phenomenons. Firstly, the biggest deformation was the floor. Secondly, the stress concentration zone was10m-20m in front of the head of the roadway and floor drum violent activities for a period of 6-7 days. Lastly, stress appeared on two walls earlier of that of roof and floor stress appearance, namely wall deformation happened in distance of head-on20m, wall deformation amount begins to tend stable convergence after50~60 meters of roadway, those were happened in the roadways which were 450m depth, 11m span and at the drivage speed of 10m/d.

Thermal-Fatigue Analysis of Turbine Discs under Complex Thermo-Mechanical Loading with Account of Plasticity and Creep Effects

2015 ◽  
Vol 725-726 ◽  
pp. 955-960 ◽  
Author(s):  
Igor Ignatovich ◽  
Artem S. Semenov ◽  
Sergey Semenov ◽  
Leonid Getsov
Keyword(s):  
Stress Concentration ◽  
Strain State ◽  
Local Strain ◽  
Complex Stress ◽  
Material Behavior ◽  
Stress Concentration Zone ◽  
Concentration Zone ◽  
Stress Strain ◽  
Thermomechanical Cycling ◽  
Stress Strain State

During operation of transport and maneuverable gas-turbine units, there are crack formation in turbine disc rims what exerted by thermomechanical cycling loads. For in-depth study of these problems we have to use theories of plasticity and creep which form the basis for determining the complex stress-strain state in the stress concentration zone for disc rims, and a modern failure criterion which can predict lifetime under conditions of simultaneous plastic and creep strain accumulation. There is a finite-element method (FEM) that allows us to evaluate the stress-strain state in a stress concentration zone for a non-elastic material behavior. With plasticity and creep theories, it is possible to determine local strain quiet reliable by FEM.

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